L297 & L298N for unipolar stepping motor

[crazybuoy]

Hi,
I am intended for build the driver for my unipolar stepping motor using L297 & L298N according to the attached schematic. I imagine it is for bipolar stepping motor because there is not one place to connect stepping motor common wire. Please show me how I can utilize this driver for unipolar stepping motor.
My unipolar stepping motor is this

 

[alexan_e]

You don't need L298 to drive a unipolar motor,
check figure 22 page 15 of this application note **broken link removed**
You can also use your own transistors instead of the ULN2075 chip.

Alex

 

[crazybuoy]

Thanks for reply. that is good but is the ULN2075 can provide me 1000 steps per second? I also read that an unipolar can be use as bipolar by omitting common wire completely. Now can I use my unipolar in this way with my above schematic?

 

[alexan_e]

You want micro stepping but i can't help you with that, i have never used it,
If your unipolar has 2 separate common wires (you will have a total of 6 wires, 3 wires for each coil which are 2 ends with one common ) then you can
but if there is only one common for both coils then you can't.

Alex

---------- Post added at 15:14 ---------- Previous post was at 15:09 ----------

I thought you meant micro stepping but you meant if the ULN can switch at 1khz.
The datasheet says that there is a turn on delay of 1us and turn off 1.5us so this can work easily at 1khz.

Alex

 

[crazybuoy]

What is timer-interrupt-frequency(steps per second) of **broken link removed**